
==== Front
Zhong Nan Da Xue Xue Bao Yi Xue Ban
Zhong Nan Da Xue Xue Bao Yi Xue Ban
zndx
Journal of Central South University Medical Sciences
1672-7347
Central South University Press Xiangya Medical College, 110 Xiangya Road, Changsha City, Hunan Province, China

39311792
1672-7347（2024）06-0961-11
10.11817/j.issn.1672-7347.2024.240215
Articles
Mediating role of inner strength in the relationship between medication literacy and medication adherence among kidney transplant patients
内在力量在肾移植患者药物素养与服药依从性关系中的中介作用（英文）http://orcid.org/0000-0002-6133-1060
王 丽萍 WANG Liping 12
方 春华 FANG Chunhua 12
聂 曼华 NIE Manhua 12
朱 莉 ZHU Li 1
http://orcid.org/0000-0003-1418-742X
刘 赛 LIU Sai 12
http://orcid.org/0000-0001-7864-2378
李 海洋 LI Haiyang 1
1 中南大学湘雅二医院临床护理学教研室，长沙 410011
1 Clinical Nursing Teaching and Research Section, Second Xiangya Hospital, Central South University, Changsha 410011
2 中南大学湘雅二医院肾脏移植科，长沙 410011
2 Department of Kidney Transplantation, Second Xiangya Hospital, Central South University, Changsha 410011, China
TIAN Pu english-editor
WANG Liping, Email: wanglp@csu.edu.cn, ORCID: 0000-0002-6133-1060

LIU Sai, Email: liusai0129@csu.edu.cn, ORCID: 0000-0003-1418-742X
LI Haiyang, Email: lihaiyang1012@csu.edu.cn, ORCID: 0000-0001-7864-2378
28 6 2024
49 6 961971
31 3 2024
©Journal of Central South University (Medical Science). All rights reserved.
2024
https://creativecommons.org/licenses/by-nc-nd/4.0/ (Open access): This is an open access article under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) (https://creativecommons.org/licenses/by-nc-nd/4.0/)。
Objective

Compared with long-term renal replacement therapy, kidney transplantation is the ideal treatment for end-stage renal disease (ESRD), significantly extending patient life and improving quality of life. Kidney transplant patients need to adhere to lifelong immunosuppressive medication regimens, but their medication adherence is generally poor compared with other organ transplant recipients. Medication adherence is closely related to medication literacy and psychological status, yet related studies are limited. This study aims to investigate the current status of medication adherence, inner strength, and medication literacy in kidney transplant patients, analyze the relationships among these 3 factors, and explore the mediating role of inner strength in the relationship between medication literacy and medication adherence.

Methods

A cross-sectional survey was conducted from March to October 2023 involving 421 patients aged≥18 years who visited kidney transplantation outpatient clinics at 4 tertiary hospitals in Hunan Province. The inner strength, medication literacy, and medication adherence of kidney transplant patients were investigated using the Inner Strength Scale (ISS), the Chinese version of the Medication Literacy Assessment in Spanish and English (MedLitRxSE), and the Chinese version of the Morisky Medication Adherence Scale-8 (C-MMAS-8), respectively. Univariate analysis was performed to examine the effects of demographic and clinical data on medication adherence. Correlation analysis was conducted to explore the relationships among medication literacy, medication adherence, and inner strength. Significant variables from univariate and correlation analyses were further analyzed using multiple linear regression, and the mediating effect of inner strength was explored.

Results

Among the 421 questionnaires collected, 408 were valid, with an effective rate of 96.91%. The scores of C-MMAS-8, MedLitRxSE, and ISS were 6.64±1.16, 100.63±14.67, and 8.47±4.03, respectively. Among the 408 patients, only 86 (21.08%) patients had a high level of medication adherence, whereas 230 (56.37%) patients had a medium level of medication adherence, and 92 (22.55%) patients had poor medication adherence. Univariate analysis indicated that the kidney transplant patients’ age, marital status, education levels, years since their kidney transplant operation, number of hospitalizations after the kidney transplant, and adverse drug reactions showed significant differences in medication adherence (all P<0.05). Correlation analysis showed that inner strength positively correlated with both medication literacy (r=0.183, P<0.001) and medication adherence (r=0.201, P<0.001). Additionally, there was a positive correlation between medication adherence and medication literacy (r=0.236, P<0.001). Inner strength accounted for 13.22% of the total effect in the mediating role between medication literacy and medication adherence.

Conclusion

The level of medication adherence among kidney transplant patients needs improvement, and targeted intervention measures are essential. Inner strength mediates the relationship between medication literacy and medication adherence in these patients. Healthcare professionals should focus on enhancing medication literacy and supporting patients’ inner strength to improve medication adherence.

目的

与长期肾脏替代治疗相比，肾移植是治疗终末期肾病(end-stage renal disease，ESRD)最为理想的方法，能够显著延长患者生命，提高患者的生活质量。肾移植患者需要终身规范服用免疫抑制药物，与其他器官移植患者相比，肾移植患者服药依从性差。服药依从性与药物素养、心理状态密切相关，而相关研究较少。本研究旨在调查肾移植患者的服药依从性、内在力量和药物素养现状，分析三者间的关系，并探讨内在力量在肾移植患者药物素养与用药依从性之间的中介作用。

方法

选取2023年3至10月在湖南省4家三级甲等医院肾移植门诊就诊且年龄≥18岁的421例患者进行横断面调查。分别采用内在力量量表(Inner Strength Scale，ISS)、中文版用药素养评估量表(Chinese version of medication Literacy Assessment in Spanish and English，MedLitRxSE)和中文版Morisky用药依从性量表-8(Chinese version of the Morisky Medication Adherence Scale-8，C-MMAS-8)对肾移植患者的内在力量、药物素养和服药依从性进行评估。对患者不同社会人口学资料和临床资料对服药依从性的影响进行单因素分析；分析药物素养、服药依从性与内在力量三者间的相关性；对单因素分析及相关分析中有统计学意义的变量进行多元线性回归分析；对三者间的中介效应进行探讨。

结果

在回收的421份调查问卷中，408份调查问卷为有效问卷，有效率为96.91%。肾移植患者C-MMAS-8、MedLitRxSE、ISS得分依次为6.64±1.16、100.63±14.67、8.47±4.03。408例患者中仅86例(21.08%)患者服药依从性水平高，230例(56.37%)患者服药依从性为中等水平，92例(22.55%)患者服药依从性水平较低。单因素分析结果显示：年龄、婚姻状况、受教育程度、肾移植手术年限、肾移植术后住院次数及药物不良反应对患者服药依从性的影响均有统计学意义(均P<0.05)。相关性分析结果显示：内在力量与药物素养(r=0.183，P<0.001)和服药依从性(r=0.201，P<0.001)呈显著正相关，药物素养与服药依从性也呈正相关(r=0.236，P<0.001)。内在力量在肾移植患者用药素养与用药依从性的中介效应关系中占总效应的13.22%。

结论

肾移植患者的药物依从性水平有待改善，制订相应的干预措施势在必行。内在力量在肾移植患者药物素养与服药依从性之间起中介效应，医护人员应注重提高肾移植患者药物素养，同时关注患者内在力量，提高肾移植患者的服药依从性。

内在力量
药物素养
服药依从性
肾移植
inner strength
medication literacy
medication adherence
kidney transplant patients
the Natural Science Foundation of Hunan Province, China2024JJ9201
==== Body
pmcWith the development of transplantation surgery, kidney transplant (KT) has become the most effective treatment for end-stage renal disease (ESRD)[1-3], providing patients with a better quality of life and survival than dialysis. However, after KT, patients must adhere to a lifelong medication regimen, learning to adapt to their new lifestyle and changing social roles[3-5]. Adherence is important in maintaining the stability of renal function after transplant. Appropriate adherence behavior can prolong the lifespan of the transplanted organ and the patient’s survival[6]. Poor medication adherence can lead to various problems[7-10], such as acute rejection[11], graft loss[8],and increased healthcare costs[12]. Medication adherence in KT patients mainly refers to adherence to immunosuppressive agents. Immunosuppressive treatment regimen after KT is relatively complex, often involving the combined use of multiple drugs, which poses strict requirements on the daily medication-taking of KT patients. However, at present, the problem of medication-taking behavior among KT patients in China is prominent, with poor medication adherence, which is a phenomenon that urgently needs attention and improvement.

The proportion of non-adherence with immunosuppressants in KT patients varied from 12% to 55%[13-16]. Additionally, it is concerning that 1.58% of KT patients stopped taking immunosuppressants altogether[13]. Considering the unsatisfactory level, researchers[17-18] have concentrated on ways to improve a patient’s medication adherence, such as reducing the number of drugs and developing relevant medication reminder systems, which can improve patients’ medication adherence to some extent, but still insufficient. During the intervention process, these studies have overlooked the patients’ inner motivation, consequently failing to sustain behavioral changes and hence, failing to effectively improve patients’ medication adherence. They also do not delve into the underlying mechanisms among the various factors influencing medication adherence. It is necessary to analyze the influencing factors and fully explore the potential mechanism. Various associated factors may contribute to poor or nonadherence, such as age, employment status, race, income, health literacy, marital status, gender, personality, and time of post-transplant[14, 19-21]. Psychological factors also significantly affect medication adherence, including illness perceptions, inner strength, and beliefs about treatment[14-15]. In the relevant research on influencing factors for KT patients, psychological factors such as inner strength are rarely incorporated.

Medication literacy is the embodiment of health literacy in the field of medicine, specifically the ability of individuals to accurately obtain, understand, and evaluate drug information and to make appropriate decisions and choose appropriate behaviors[22].A low level of medication literacy can lead to difficulties in accurately identifying relevant drug information, using the correct drugs, and failing to achieve the expected therapeutic effect, resulting in a low level of patients’ medication adherence[23].However, the relationship between medication literacy and medication adherence in KT patients is unclear.

Inner strength is the ability of the body to actively cope with life’s adversities[24]. Patients with high inner strength can effectively maximize external resources to control the development and treatment of the disease, improving treatment compliance and achieving a healthier condition while living with the disease[25]. Inner strength has been proved to be an important factor that affects medication adherence in some patients with chronic diseases such as hypertension and diabetes, but no similar studies have been done among KT patients.

Inner strength is closely related to medication literacy[23].Patients with high medication literacy have high inner strength, and they can take the initiative to find their own physiological and psychological adjustment methods when facing the disease[23]. Patients with high medication literacy also have higher levels of inner strength[26]. Another study[27] has shown that patients with high drug literacy have higher levels of self-health cognition and management and relatively high inner strength. The relationship between the inner strength and medication literacy of KT patients is worth exploring.

Based on the above literature review, medication literacy, inner strength, and medication adherence are interrelated, and we speculate that there may be a mediating effect among them. The self-efficacy is a mediating variable between medication literacy and medication adherence in patients with hypertension[28]. Both self-efficacy and inner strength are concepts related to motivation in psychology, representing inner psychological factors that can promote personal development. Both inner strength and self-efficacy play crucial roles in shaping and influencing a person’s behavior. Therefore, we hypothesize that inner strength may also be a mediating variable.

This study aims to investigate the current status of medication adherence, inner strength, and medication literacy in KT patients, analyze the relationships among these 3 factors, and explore the mediating role of inner strength in the relationship between medication literacy and medication adherence.

1 Subjects and methods

1.1 Study design

A cross-sectional survey was conducted from March to October 2023 involving patients who visited kidney transplantation outpatient clinics at 4 tertiary hospitals in Hunan Province. We adopted the purposive sampling method to collect relevant information from KT patients who completed 3 different evaluating scales in a questionnaire. Each patient signed the informed consent spent about 15 to 20 minutes on their questionnaire. This study was approved by the Ethics Committee of the Second Xiangya Hospital of Central South University (No. LYF2022107).

1.2 Participants and data collection

Inclusion criteria of patients for this study: 1) Aged≥18 years; 2) had received a KT within at least one month; 3) spoke Chinese and communicated well with others; 4) understood the purpose and process of the study and agreed to participate. Exclusion criteria of patients: 1) Other serious diseases such as cancer or a cardiovascular disease; 2) concomitant psychological or mental disease; 3) secondary KT. The research team that administered the questionnaire to the KT patients comprised four trained researchers. Two went together to the target hospital and informed the KT patients in advance about the purpose, content, significance, and precautions of this study. The KT patients also signed the informed consent form. For illiterate patients, we had to contact the patients and their families to obtain their consent. We read the contents of the questionnaire word by word to the patients, who provided corresponding answers. We collected all questionnaires on-site and checked for missing items to ensure data integrity and ultimately distributed 421 surveys.

1.3 Measurement tools

Questionnaires were used to collect data including the sociodemographic and disease-related information. The inner strength, medication literacy, and medication adherence of KT patients were investigated using the Inner Strength Scale (ISS), the Chinese version of the Medication Literacy Assessment in Spanish and English (MedLitRxSE), and the Chinese version of the Morisky Medication Adherence Scale-8 (C-MMAS-8), respectively.

1.3.1 Sociodemographic and clinical characteristics

We collected the following information about KT patients’ sociodemographic and clinical characteristics using a self-developed questionnaire that covered the following topics: Age, gender, marital status, education level, working status, annual income, type of medical insurance, place of residence, KT operation years, number of drugs prescribed, adverse drug reaction, and number of hospitalizations after the KT.

1.3.2 ISS

ISS has 5 dimensions (20 items): Courage (3 items), firmness (4 items), creativity (3 items), connectivity (5 items), and flexibility (5 items)[29]. We adopted a 6-point Likert scale, ranging from completely disagree 1 to completely agree 6. The scale’s total score was 20 to 120 points. The higher the score, the stronger the subjects’ inner strength. The Cronbach’s alpha value in this study was 0.85.

1.3.3 MedLitRxSE

MedLitRxSE is a universal scale used to assess a patient’s level of medication literacy[30]. In this study, we adopted the Chinese version of the medication literacy scale that ZHENG et al.[31] conducted in 2016. The scale consists of 14 items, and 4 different cases are simulated when the scale is used. The use scenarios includes insulin injection in accordance with a doctor’s advice, taking fever prescription medication for children, identifying prescription drug names and calculating dosage, and understanding of medication labels. The scoring is binary (one point for a correct answer and zero points for an incorrect answer). The total score of the scale ranges from 0 to 14, with the higher score indicating a higher level of medication literacy. The Cronbach’s alpha value in this study was 0.91.

1.3.4 C-MMAS-8

C-MMAS-8 is a concise, pragmatic and cost-effective self-administered measure, mainly used to evaluate medication adherence level[32], which includes 8 items, with yes and no as the answer options for 7 items. The last question is answered on a 5-point Likert scale, with answers being never (1), occasionally (0.75), sometimes (0.50), always (0.25), and all time (0). The total score on this scale ranges from 0 to 8, with higher scores indicating better adherence. We applied Morisky’s suggested cut-off point of 6: A total score<6 indicated low adherence, score=8 indicated high adherence, and score≥6 and <8 indicated medium adherence. The Cronbach’s alpha value in this study was 0.83.

1.4 Theoretical framework

The described mediation analytical framework helped guide the analysis plan[33]. The X, M, and Y represented medication literacy, inner strength, and medication adherence, respectively. Variable M was a mediator if X significantly predicted Y directly (Path c in Figure 1), X significantly predicted M (Path a in Figure 1), or M significantly predicted Y after controlling for X (Path b in Figure 1). Path c’ represented the direct effect of X on Y after controlling for M (Path c’ in Figure 1). If the regression correlation coefficient of Path c’ was not significant, then we considered this mediating effect of M as complete mediation. On the contrary, if it was significant, then we considered this mediating effect of M as partial mediation. We calculated the mediation effect value as a×b, and the ratio of the mediating effect with the total effect=a×b/c.

Figure 1 Theoretical framework of this study

1.5 Statistical analysis

SPSS statistics software version 26.0 was used for statistical analysis. All continuous variables with a normal distribution were presented as means ± standard deviation (SD). The categorical variables were presented as numbers and percentages. The independent-sample t test or analysis of variance was used to compare the scores of 3 scales among KT patients with different sociodemographic and clinical characteristics. A univariate analysis was conducted on medication adherence based on the sociological and disease characteristics of the study subjects. Pearson correlation coefficient was used to determine the correlation among inner strength, medication literacy, and medication adherence. We took meaningful variables form the univariate analysis and correlation analysis as independent variables, and medication adherence as a dependent variable for multiple linear regression analysis. The significance of the mediating effect of inner strength on the relationship between medication literacy and medication adherence was confirmed by the Hayes PROCESS 4.1 model and verified by Bootstrapping with 5 000 samples. Differences were considered significant at P<0.05.

2 Results

A total of 421 questionnaires were distributed in this survey, and 408 were valid yielding a 96.91% response rate. In addition, 86 (21.08%) patients had high medication adherence, 230 (56.37%) had moderate medication adherence, and 92 (22.55%) had low medication adherence.

2.1 Univariate analysis of medication adherence in KT patients

Among 408 KT patients, 214 (52.45%) were aged 18 to 44 years, 256 (62.75%) were male, and most (77.94%) patients were married. The results of univariate analysis indicated that age, marital status, education level, KT operation years, adverse drug reaction and number of hospitalizations after kidney transplantation had statistically significant effects on patients’ medication adherence (all P<0.05, Table 1).

Table 1 Univariate analysis of medication adherence among kidney transplant patients (n=408)

Items	No.	Proportion/%	Medication adherence	F	P	
Age/years	18-44	214	52.45	6.78±1.06	3.434	0.033	
45-59	184	45.10	6.48±1.25	
≥60	10	2.45	6.75±1.22	
Gender	Male	256	62.75	6.66±1.20	0.143	0.705	
Female	152	37.25	6.62±1.09	
Marital status	Unmarried	60	14.71	6.95±1.02	4.212	0.006	
Married	318	77.94	6.58±1.17	
Divorce	28	6.86	6.80±1.16	
Others	2	0.49	4.50±0.00	
Education level	Junior middle school or below	110	26.96	6.38±1.25	3.996	0.008	
Senior high school	124	30.39	6.58±1.24	
Junior college or Bachelor degree	164	40.20	6.86±1.01	
Postgraduate degree	10	2.45	6.75±0.90	
Working state	Employed	170	41.67	6.66±1.00	0.073	0.787	
Unemployment	238	58.33	6.63±1.26	
Annual income/Yuan per month	≤3 000	136	33.33	6.50±1.19	1.982	0.116	
3 001-5 000	146	35.78	6.82±1.05	
5 001-8 000	72	17.65	6.55±1.41	
>8 000	54	13.24	6.64±0.96	
Type of medical insurance	Employee medical insurance	174	42.65	6.76±1.02	1.764	0.173	
Resident medical insurance	200	49.02	6.54±1.27	
Others	34	8.33	6.69±1.12	
Place of residence	Urban	276	67.65	6.67±1.08	0.589	0.443	
Rural	132	32.35	6.58±1.31	
Years since their kidney transplant operation	<1	122	29.90	7.01±1.13	4.793	0.001	
1-3	76	18.63	6.47±1.15	
3-5	90	22.06	6.43±1.25	
5-10	72	17.65	6.62±0.97	
≥10	48	11.76	6.42±1.17	
Number of drugs prescribed	≤3	36	8.82	6.74±1.52	0.235	0.791	
4-5	146	35.79	6.60±1.13	
>5	226	55.39	6.66±1.12	
Adverse drug reaction	Yes	64	15.69	6.32±1.19	6.470	0.002	
No	294	72.06	6.77±1.05	
Unclear	50	12.25	6.31±1.57	
Number of hospitalizations after kidney transplantation	≤3	232	56.86	6.87±1.06	10.999	<0.001	
3-6	84	20.59	6.45±1.27	
>6	92	22.55	6.26±1.17	

2.2 Analysis of relationship between medication literacy, inner strength, and medication adherence in KT patients

The scores for inner strength, medication literacy, and medication adherence were 100.63±14.67, 8.47±4.03, and 6.64±1.16, respectively.

Correlation analysis showed that inner strength was positively correlated with both medication literacy (r=0.183, P<0.001) and medication adherence (r=0.201, P<0.001; Table 2). Additionally, there was a positive correlation between medication adherence and medication literacy (r=0.236, P<0.001; Table 2).

Table 2 Correlation between kidney transplantation patients’ medication literacy, inner strength, and medication adherence

Variables	Medication literacy	Inner strength	Medication adherence	
Medication literacy	1	—	—	
Inner strength	0.183***	1	—	
Medication adherence	0.236***	0.201***	1	
***P<0.001.

2.3 Regression analysis of the effects of demographic characteristics, medication literacy, and inner strength on medication adherence in KT patients

The medication literacy, inner strength, and the number of hospitalizations after KT entered the regression equation and were independent influencing factors of medication adherence (all P<0.05, Table 3).

Table 3 Multiple linear regression analysis of medication adherence in kidney transplant patients

Variable	B	Sb	B’	t	P	
Constant	6.028	0.553	—	10.897	<0.001	
Age	-0.53	0.106	-0.025	-0.498	0.619	
Marital status	-0.205	0.116	-0.085	-1.763	0.079	
Education level	0.086	0.069	0.064	1.250	0.212	
KT operation years	-0.045	0.045	-0.054	-1.017	0.310	
Adverse drug reaction	-0.022	0.107	-0.010	-0.205	0.838	
Medication literacy	0.045	0.015	0.157	3.065	0.002	
Inner strength	0.011	0.004	0.138	2.858	0.004	
Number of hospitalizations after KT	-0.221	0.075	-0.157	-2.949	0.003	
KT: Kidney transplant.

2.4 Analysis of mediating role of inner strength between medication literacy and medication adherence

Figure 2 demonstrates the mediating role of inner strength in the relationship between medication literacy and medication adherence. Table 4 presents a description of the mediating effects of inner strength between medication literacy and medication adherence. The results showed that after controlling for sociodemographic variables, we identified a significant total effect of medication literacy on medication adherence (Path c: c=0.068 1, t=4.899 6, P<0.001). In path a, medication literacy had a positive impact on inner strength (Path a: a=0.667 0, t=3.752 5, P<0.001). In path b, inner strength had a positive impact on medication adherence (Path b: b=0.012 9, t= 3.363 2, P<0.001). In addition, in path c’, medication literacy had a positive impact on medication adherence (Path c’: c’=0.059 5, t=4.261 8, P<0.001; Table 4). We calculated the mediation effect value as 0.667 0×0.012 9, specifically, 0.009, and the ratio of the mediating effect over the total effect was 13.22% (0.009/0.068 1).

Figure 2 Mediating role of inner strength in the relationship between medication literacy and medication adherence

Table 4 Summary of the mediating effects of inner strength between medication literacy and medication adherence

Effect	Independent variables	Dependent variables	B	SE	t	P	95% CI	
Total effect (c)	X	Y	0.068 1	0.013 9	4.899 6	<0.001	0.040 8-0.095 5	
Indirect effect (a)	X	M	0.667 0	0.177 7	3.752 5	<0.001	0.317 6-1.016 4	
Indirect effect (b)	M	Y	0.012 9	0.003 8	3.363 2	<0.001	0.005 4-0.020 4	
Direct effect (c’)	X	Y	0.059 5	0.014 0	4.261 8	<0.001	0.032 1-0.087 0	
B: Unstandardized coefficient; SE: Standard error; X: Medication literacy; M: Inner strength; Y: Medication adherence.

The results of the analysis demonstrated that inner strength had a significant mediating effect, and zero was not included (95% CI 0.003 to 0.017, Z=2.504, P=0.012).

3 Discussion

Adherence to immunosuppressive drugs is critical for KT patients. In this study, only 21.08% of KT patients had high adherence to their medication regimens. There may be several reasons for the unsatisfactory medication adherence of KT patients. Firstly, the medication regimen of immunosuppressants in KT patients involves combination medication and other adjuvant drugs, which need to be taken several times a day. Other study[34] has showed that the more times a day patients need to take medication, the worse the medication adherence. Secondly, the majority of KT patients return to their daily activities about one year after surgery, and their work and life are often interrupted by drug-taking events，resulting in their inability to take medication as prescribed. We found 22.55% of KT patients had a low level of medication adherence, which is slightly less than the 32.4% found in other study[14]. This difference may be due to the large proportion of patients within one year after KT in this study, because these patients need to go to the hospital for reexamination more frequently than other patients. During the reexamination, medical staff will consciously remind them to take medicine on time. However, the proportion of middle-aged and young patients is high.

In this study, medication adherence of KT patients was positively correlated with medication literacy, and the higher the level of medication literacy, the better the medication adherence, of which the conclusion is consistent with JIANG’s research[23]. Patients with a high level of medication literacy have a fuller understanding of the drug information and less doubt about drug use, which is conducive to enhancing the confidence of patients to persist in drug use[35]. Conversely, patients with insufficient medication literacy may not understand the relevant information well enough to make correct judgments[36]. Studies[37-38] have shown that the current drug use instructions are too complex, which is also one of the important factors affecting drug literacy. Therefore, medical workers should improve the medication literacy of KT patients to promote their medication adherence, by providing explanations of various forms of medication information during hospitalization, continuing drug-related information services while they are at home, and simplified drug specifications.

There was a positive correlation between inner strength and medication adherence in KT patients in this study. Inner strength is the ability of the body to resist stress[23]. Patients with high inner strength are more likely to actively seek solutions when facing the interference of work and life caused by medication. They tend to seek help and support from medical staff, family members, and friends, and they strive to improve their self-management ability. The support of family members and medical staff can enhance the inner strength of patients to some extent[23]. Therefore, clinical medical staff in KT centers should pay attention to improving patients’ inner strength, give patients all-round support and care, and help them better cope with the challenges in the treatment process. Therefore, we must focus on cultivating and enhancing patients’ inner strength.

In this study, inner strength was positively correlated with medication literacy. Another study[23] showed that patients with high medication literacy could better stimulate their own potential, and their inner strength increases. These individuals could better cope with the impact of long-term medication on work and life, making them more likely to strictly follow doctors’ advice and ensure taking medication on time and in full dosage.

Through this study, we explored how medication literacy positively affects medication adherence and how inner strength plays an important mediating role. Patients with high medication literacy will seek help and get support to stimulate their potential, which enhances their inner strength and helps them overcome the impact of medication, thereby improving medication adherence. This result confirms that we should introduce inner strength interventions to improve the medication adherence of KT recipients. Traditional interventions for medication compliance usually focus on improving patients’ knowledge and drug literacy through health education[39]. Firstly, Health-care professionals and caregivers should clearly communicate the necessity and importance of long-term medication adherence to patients, dispelling any doubts or misunderstandings they may have. Secondly, attention should be paid to patients’ inner thoughts and emotions. Active and effective interventions should be carried out to maintain a high level of inner strength. This includes monitoring patients’ psychological state, especially their attitude toward drug treatment, and providing positive communication and psychological support to strengthen their inner strength, improve their confidence in treatment, and enhance medication adherence. Finally, as the primary agents for improving patients’ medication literacy, medical staff should use different methods to continuously strengthen the education of patients’ medication knowledge and help them establish the correct concept of medication.

This study still has some limitations. Firstly, all measurement tools relied on self-reporting, leading to potentially subjective patient outcomes. Secondly, the study’s participants were solely recruited from four organ transplantation centers located in Changsha City, Hunan Province, limiting the geographical diversity. Lastly, given that most participants were under 60 years of age, our findings may not accurately reflect the experiences of patients over 60. Nevertheless, we maintain that our results offer valuable insights for future research directions. In the future, we aim to expand our study by incorporating patients from a broader range of regions and integrating objective indicators into our research methodology.

In summary, the medication adherence of KT patients still requires improvement. Medication literacy has a direct relationship with medication adherence, and it can also affect medication adherence indirectly through internal strength. To enhance the medication adherence of KT patients, healthcare professionals can focus on the following 2 aspects: Strengthening the promotion and education of drug knowledge to improve patients’ medication literacy; meanwhile, health professionals can fully tap into patients’ inner potential by paying attention to their inner thoughts and emotions, providing psychological support, boosting their confidence in taking medication, and emphasizing the cultivation of patients’ inner strength.

Funding Statement

This work was supported by the Natural Science Foundation of Hunan Province, China (2024JJ9201).

Conflict of Interest

The authors declare that they have no conflicts of interest to disclose.

AUTHORS’CONTRIBUTIONS

WANG Liping Research design, data collecting and analysis, and paper writing; FANG Chunhua and NIE Manhua Paper modification; ZHU Li and LI Haiyang Data collecting and analysis; LIU Sai Paper supervision and revision. The final version of the manuscript has been approved and read by all authors.

Note

http://xbyxb.csu.edu.cn/xbwk/fileup/PDF/202406961.pdf

http://dx.chinadoi.cn/10.11817/j.issn.1672-7347.2024.240215
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Reference

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